A little background information

Delta RPMs (DRPMs) are very similar to binary (regular) RPMs. The main difference is that DRPMs contain only the changes between two versions of an RPM package. This allows you to do full updates in a lot less time - Instead of downloading a full 10MB for an update where only 50kb of content changed, for example, you can now download only that 50kb of change and apply it to your system.

Not only will you save on bandwidth since you're only downloading in the changes in a package, but you'll also cut down on the time it takes to download and apply the packages.

Presto is a project which brings deltarpm and yum together; In other words, letting you use yum to apply DRPMs.

Installing yum-presto

The first step toward setting up Presto is installing the yum plugin:

yum -y install yum-presto

Configure the Updates repository

Next, we need to configure your updates repository to download deltarpm packages instead of the full ones. In the /etc/yum.repos.d/fedora-updates.repo file you'll find two lines that looks like this in the [updates] section:

The pound sign makes Yum ignore the line that it's on, so essentially we're telling yum to ignore the base repository and any mirrors. The line which was added tells yum to use the presto-enabled mirrors instead.

That's it! Now run you can use yum or yumex as normal and benefit from the advantages of deltarpms.